<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        //1.创建FormData实例
        var fd = new FormData();
        //2.调用append函数，向fd中追加数据
        fd.append('uname', 'zs');
        fd.append('upwd', '123456');
        //3.创建xhr对象
        var xhr = new XMLHttpRequest();
        //4.指定请求类型和url地址
        xhr.open('POST', 'http://www.liulongbin.top:3006/api/formdata');
        //5.直接提交FormData对象， 这与提交网页表单的效果完全一样
        xhr.send(fd);
        xhr.onreadystatechange = function () {
            if (xhr.readyState === 4 && xhr.status === 200) {
                console.log(JSON.parse(xhr.responseText));
            }
        }
    </script>
</body>

</html>